• Welcome to PlumbersForums.net - The international free plumbing advice forum. Professional plumbers sharing advice with fellow plumbers and DIY alike. Register for free today! - Checkout the Plumbing Advice forum and then our Plumbing Videos area which still needs populating.

Discuss Shower Waste through concrete floors - any advice ? in the Plumbing Forum | Plumbing Advice area at PlumbersForums.net

Hi everyone,
First a quick bit of background : I'm English, living in France, and renovating a 1960s house, which has pretty much needed to be stripped back to the studs, and started again. Full new electrical refit, plumbing refit, walls, ceilings &etc. It took about a year-and-a-half (as it's a DIY "project") to strip internally, and we're now rebuilding. Living in it as well, and we have sufficiently finished (haven't installed architrave for the doors / skirting boards for example) a Kitchen, Living Room, Dining Room, and 2 Bedrooms. Note the absence of "bathroom". We have a bit of a "Heath Robinson" set up for the toilet and bath, which works, but is far from ideal. Next room to tackle, though, will be the bathroom.

So - here's my question / request for help.
Our floors are all pretty solid concrete; sometime with breeze block equivalents, but they're basically 23cm or so thick. I want to install a shower tray in the bathroom, and all of the standard solutions for a trap have a horizontal exit with a 45o connector. This is ideal for houses with floor boards and beams - plenty of videos on SkillBuilder / Youtube / PlumberParts, but installing this in a solid concrete floor would be a nightmare, plus the risk of loss of structural integrity, I would imagine.

I've come across a few vertical traps, which look like they might be the solution (less drill out of the floor), like this one
which would / should enable a single vertical drill hole though to the floor below, which I can then take through a false ceiling to the 100mm stack.

If you've ever used these, I'd appreciate your feedback on this as an idea ? Also, I would ideally want to have, in the ceiling below, a 90o bend to reduce the loss of the ceiling height (in the false wall), but is that just foolish ?, or should I go for a long sweep (or, realistically, 2 x 45o joints)

Thanks in advance for any suggestions / feedback &etc.

Hi Shaun,
Honestly I'm not sure on the exact construction specifics. That said, in the 1970s, they installed a staircase to the top floor, that, when we removed the wallboard, showed the construction of the top floor ceiling. Additionally, in the original bathroom, they had drilled through a shower outlet (which I've tidied up and will use to feed the bath waste). I've attached pictures. The concrete floor with the red brick underneath is the top floor. The concrete floor with the steel just visible is also the top floor (directly opposite the other shot), This will have, though, been a "new" steel in the 1970s when the floor was carved out to install the stairs. The final picture is the first floor to ground floor, and was was originally a shower waste.

Please let me know if this didn't answer the question, and thanks for your interest in the subject !



  • IMG_1238.JPG
    467.4 KB · Views: 0
  • IMG_1239.JPG
    488.8 KB · Views: 0
  • IMG_1241.JPG
    411.7 KB · Views: 0

Reply to Shower Waste through concrete floors - any advice ? in the Plumbing Forum | Plumbing Advice area at PlumbersForums.net